org.apache.commons.lang
public class RandomStringUtils extends Object
Operations for random String
s.
Currently private high surrogate characters are ignored. These are unicode characters that fall between the values 56192 (db80) and 56319 (dbff) as we don't know how to handle them. High and low surrogates are correctly dealt with - that is if a high surrogate is randomly chosen, 55296 (d800) to 56191 (db7f) then it is followed by a low surrogate. If a low surrogate is chosen, 56320 (dc00) to 57343 (dfff) then it is placed after a randomly chosen high surrogate.
Since: 1.0
Version: $Id: RandomStringUtils.java 471626 2006-11-06 04:02:09Z bayard $
Constructor Summary | |
---|---|
RandomStringUtils()
|
Method Summary | |
---|---|
static String | random(int count) Creates a random string whose length is the number of characters specified. Characters will be chosen from the set of all characters. |
static String | random(int count, boolean letters, boolean numbers) Creates a random string whose length is the number of characters specified. Characters will be chosen from the set of alpha-numeric characters as indicated by the arguments. |
static String | random(int count, int start, int end, boolean letters, boolean numbers) Creates a random string whose length is the number of characters specified. Characters will be chosen from the set of alpha-numeric characters as indicated by the arguments. |
static String | random(int count, int start, int end, boolean letters, boolean numbers, char[] chars) Creates a random string based on a variety of options, using default source of randomness. This method has exactly the same semantics as
|
static String | random(int count, int start, int end, boolean letters, boolean numbers, char[] chars, Random random) Creates a random string based on a variety of options, using supplied source of randomness. If start and end are both |
static String | random(int count, String chars) Creates a random string whose length is the number of characters specified. Characters will be chosen from the set of characters specified. |
static String | random(int count, char[] chars) Creates a random string whose length is the number of characters specified. Characters will be chosen from the set of characters specified. |
static String | randomAlphabetic(int count) Creates a random string whose length is the number of characters specified. Characters will be chosen from the set of alphabetic characters. |
static String | randomAlphanumeric(int count) Creates a random string whose length is the number of characters specified. Characters will be chosen from the set of alpha-numeric characters. |
static String | randomAscii(int count) Creates a random string whose length is the number of characters specified. Characters will be chosen from the set of characters whose
ASCII value is between |
static String | randomNumeric(int count) Creates a random string whose length is the number of characters specified. Characters will be chosen from the set of numeric characters. |
RandomStringUtils
instances should NOT be constructed in
standard programming. Instead, the class should be used as
RandomStringUtils.random(5);
.
This constructor is public to permit tools that require a JavaBean instance to operate.
Creates a random string whose length is the number of characters specified.
Characters will be chosen from the set of all characters.
Parameters: count the length of random string to create
Returns: the random string
Creates a random string whose length is the number of characters specified.
Characters will be chosen from the set of alpha-numeric characters as indicated by the arguments.
Parameters: count the length of random string to create letters if true
, generated string will include
alphabetic characters numbers if true
, generated string will include
numeric characters
Returns: the random string
Creates a random string whose length is the number of characters specified.
Characters will be chosen from the set of alpha-numeric characters as indicated by the arguments.
Parameters: count the length of random string to create start the position in set of chars to start at end the position in set of chars to end before letters if true
, generated string will include
alphabetic characters numbers if true
, generated string will include
numeric characters
Returns: the random string
Creates a random string based on a variety of options, using default source of randomness.
This method has exactly the same semantics as
(int,int,int,boolean,boolean,char[],Random)
, but
instead of using an externally supplied source of randomness, it uses
the internal static Random instance.
Parameters: count the length of random string to create start the position in set of chars to start at end the position in set of chars to end before letters only allow letters? numbers only allow numbers? chars the set of chars to choose randoms from.
If null
, then it will use the set of all chars.
Returns: the random string
Throws: ArrayIndexOutOfBoundsException if there are not
(end - start) + 1
characters in the set array.
Creates a random string based on a variety of options, using supplied source of randomness.
If start and end are both 0
, start and end are set
to ' '
and 'z'
, the ASCII printable
characters, will be used, unless letters and numbers are both
false
, in which case, start and end are set to
0
and Integer.MAX_VALUE
.
If set is not null
, characters between start and
end are chosen.
This method accepts a user-supplied Random instance to use as a source of randomness. By seeding a single Random instance with a fixed seed and using it for each call, the same random sequence of strings can be generated repeatedly and predictably.
Parameters: count the length of random string to create start the position in set of chars to start at end the position in set of chars to end before letters only allow letters? numbers only allow numbers? chars the set of chars to choose randoms from.
If null
, then it will use the set of all chars. random a source of randomness.
Returns: the random string
Throws: ArrayIndexOutOfBoundsException if there are not
(end - start) + 1
characters in the set array. IllegalArgumentException if count
< 0.
Since: 2.0
Creates a random string whose length is the number of characters specified.
Characters will be chosen from the set of characters specified.
Parameters: count the length of random string to create chars the String containing the set of characters to use, may be null
Returns: the random string
Throws: IllegalArgumentException if count
< 0.
Creates a random string whose length is the number of characters specified.
Characters will be chosen from the set of characters specified.
Parameters: count the length of random string to create chars the character array containing the set of characters to use, may be null
Returns: the random string
Throws: IllegalArgumentException if count
< 0.
Creates a random string whose length is the number of characters specified.
Characters will be chosen from the set of alphabetic characters.
Parameters: count the length of random string to create
Returns: the random string
Creates a random string whose length is the number of characters specified.
Characters will be chosen from the set of alpha-numeric characters.
Parameters: count the length of random string to create
Returns: the random string
Creates a random string whose length is the number of characters specified.
Characters will be chosen from the set of characters whose
ASCII value is between 32
and 126
(inclusive).
Parameters: count the length of random string to create
Returns: the random string
Creates a random string whose length is the number of characters specified.
Characters will be chosen from the set of numeric characters.
Parameters: count the length of random string to create
Returns: the random string